This application relates to the art of lighting and, more particularly, to lights which are disguised to give the appearance of a standard light when turned off, and to provide light of a predetermined color for emergency signalling or the like when turned on. The invention is particularly applicable for use in lights of the type including a relatively small light source mounted at the base of a reflector having a reflector side wall extending outwardly from the base toward a lens. However, it will be appreciated that the invention has broader aspects and may be used in other types of lights.
Obviously, virtually all lights have a different appearance when turned on from when they are turned off. The difference in appearance is usually one of brightness or color intensity. However, a person can usually tell the color a light will have when it is turned on from the appearance of the light when it is turned off.
For certain purposes, it is desirable that a light have a certain color when turned on which is not discernible when the light is turned off. For example, vehicles used for what is known as undercover law enforcement operation frequently require emergency lights of any suitable emergency color, such as red or blue. When the emergency lights are off, it is desirable that the vehicle have the appearance of a standard family automobile or the like. These vehicles, as well as private vehicles used by auxiliary firemen or policemen, often require emergency lights for use when the vehicle is speeding to the scene of a fire, accident or crime, and it is desirable that the emergency lights not be recognizable as such when they are turned off. For vehicles of this type, it has become known to mount the emergency lights in the same location as conventional driving lights or fog lights, and to disguise the emergency lights so they will have the appearance of standard clear driving lights or yellowish fog lights when they are turned off.
Known arrangements for disguising emergency lights include that disclosed in U.S. Pat. No. 2,907,249 issued Oct. 6, 1959, to Hjermsted. In this arrangement, the entire lens is colored for imparting a color to light transmitted outwardly therethrough from a light source. The exterior surface of the lens is intermittently coated to provide a fragmentary mirror so that external light striking the fragmentary mirror will be reflected before it is imparted with the color of the lens. Arrangements of this type are very expensive because the entire exterior surface of a relatively large lens must be mirrored and the colored lens itself is of special construction. In addition, a large amount of light passes through the openings between the intermittent mirrored surface, and is reflected back out through the colored lens so that a complete disguise is not achieved. The inability to view through the lens is an indication in itself that the light is of special construction instead of being an ordinary clear driving light or fog light.
U.S. Pat. No. 3,514,589 issued May 26, 1970, to Huber discloses a disguised vehicle light having an outer panel which is adapted to appear the same as the finish of the car when the light is turned off. In the Huber arrangement, the color filter is positioned substantially completely across the reflector in front of the light source and a disguise panel is located across the light outwardly of the color filter. This arrangement itself would also give an indication of something special about the vehicle because the light would not appear to be a standard clear white driving light or a slightly yellowish fog light when turned off. The intensity of the light when turned on would also be less than that desired for an emergency light. Huber coats the exterior of a screen with a desired color and either incorporates it within another panel or positions the screen behind the panel. External light rays striking the colored outer surface of the screen will give the light the appearance of the color provided on the outer screen surface. In arrangements of this type, as well as that of Hjermsted, the lights themselves are relatively unconventional because a special outer lens or panel is required across the entire outer surface of the reflector. In addition, the disguise is easily discernible to a knowledgeable person because the interior of the light assembly cannot be seen from a location exterior of the lens. External light entering the light assemblies of Huber and Hjermsted is bound to be reflected back out through the color filter so that the disguise may be relatively incomplete.
It would be desirable to have a disguished emergency light which would give off a clear emergency color when illuminated, and would appear to be a conventional vehicle light when turned off.